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Theorem ordtri4 4582
Description: A trichotomy law for ordinals. (Contributed by NM, 1-Nov-2003.) (Proof shortened by Andrew Salmon, 25-Jul-2011.)
Assertion
Ref Expression
ordtri4  |-  ( ( Ord  A  /\  Ord  B )  ->  ( A  =  B  <->  ( A  C_  B  /\  -.  A  e.  B ) ) )

Proof of Theorem ordtri4
StepHypRef Expression
1 eqss 3327 . 2  |-  ( A  =  B  <->  ( A  C_  B  /\  B  C_  A ) )
2 ordtri1 4578 . . . 4  |-  ( ( Ord  B  /\  Ord  A )  ->  ( B  C_  A  <->  -.  A  e.  B ) )
32ancoms 440 . . 3  |-  ( ( Ord  A  /\  Ord  B )  ->  ( B  C_  A  <->  -.  A  e.  B ) )
43anbi2d 685 . 2  |-  ( ( Ord  A  /\  Ord  B )  ->  ( ( A  C_  B  /\  B  C_  A )  <->  ( A  C_  B  /\  -.  A  e.  B ) ) )
51, 4syl5bb 249 1  |-  ( ( Ord  A  /\  Ord  B )  ->  ( A  =  B  <->  ( A  C_  B  /\  -.  A  e.  B ) ) )
Colors of variables: wff set class
Syntax hints:   -. wn 3    -> wi 4    <-> wb 177    /\ wa 359    = wceq 1649    e. wcel 1721    C_ wss 3284   Ord word 4544
This theorem is referenced by:  carduni  7828  alephfp  7949
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 8  ax-gen 1552  ax-5 1563  ax-17 1623  ax-9 1662  ax-8 1683  ax-14 1725  ax-6 1740  ax-7 1745  ax-11 1757  ax-12 1946  ax-ext 2389  ax-sep 4294  ax-nul 4302  ax-pr 4367
This theorem depends on definitions:  df-bi 178  df-or 360  df-an 361  df-3or 937  df-3an 938  df-tru 1325  df-ex 1548  df-nf 1551  df-sb 1656  df-eu 2262  df-mo 2263  df-clab 2395  df-cleq 2401  df-clel 2404  df-nfc 2533  df-ne 2573  df-ral 2675  df-rex 2676  df-rab 2679  df-v 2922  df-sbc 3126  df-dif 3287  df-un 3289  df-in 3291  df-ss 3298  df-pss 3300  df-nul 3593  df-if 3704  df-sn 3784  df-pr 3785  df-op 3787  df-uni 3980  df-br 4177  df-opab 4231  df-tr 4267  df-eprel 4458  df-po 4467  df-so 4468  df-fr 4505  df-we 4507  df-ord 4548
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